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coondoggie writes "Scientists at DARPA say there are some 1,300 satellites worth over $300B sitting out in Earth's geostationary orbit (GEO) that could be retrofitted or harvested for new communications roles and it designed a program called Phoenix which it says would use a squadron 'satlets' and a larger tender craft to grab out-of-commission satellites and retrofit or retrieve them for parts or reuse." This program incorporates a design challenge aspect, in which various teams compete to design systems to effect the actual capture. From the article: "In the Zero Robotics challenge, three finalist teams emerged from a series of four, one-week qualifying rounds: "y0b0tics!" (Montclair, NJ); "The Catcher in the Skye" (Sparta, NJ); and "Nitro" (Eagleville, PA). Then in June the teams gathered at the Massachusetts Institute of Technology to watch via video link as their algorithms were tested on board the ISS, DARPA said. The algorithms were applied across three situations in which the SPHERES satellite simulated an active spacecraft approaching an object tumbling through space. In each scenario, at least one of the teams was able to approach the tumbling target and remain synchronized within the predefined capture region, DARPA said."

Satellites are already being reprogrammed and repurposed in this manner. This allows new functionality without others knowing you are launching something which throws up read flags. In 2004 there was a program to refit a

...it is because the Aliens are still using modems. They are far from their home planets, have been unable to update their technology for hundreds of years and we here on earth have now surpassed them in some tech areas, but they can still [NO CARRIER]

But isn't this technically a form of 'space salvage' or perhaps 'space piracy'? Did they get permission to retrofit these satellites from the owners? What's the 'abandonment period' for spaceborne objects to be considered 'up for grabs'? Assuming they're not already, how long until the military is using this either to capture and repurpose foreign satellites, or perhaps use them as disguised weapons to cause conflict between 3rd party nations?

And that's just what I came up with in the first 15 seconds of reading the summary.

Some of them might. Satellites need fuel to stay in the right place, and to keep themselves pointing in the right direction (solar panels at the Sun, antennas at the Earth). It's called station keeping [wikipedia.org]. Sometimes otherwise functioning communications satellites run out of fuel, and end up being useless because they're pointing the wrong way. Refuelling them can give them a new life. If there's still fuel but the thrusters or reaction wheels break, you have the same problem. That might be fixed by swapping th

I doubt that any sensitive satellites go up without the ability to to at least neutralise's sensitive info that may be on them and in such a way that that tampering would be next to imposable. Besides capturing a active satellite is far easier than decommissioned as they are very stable in there orbit. Hubble has been "caught" several times for maintenance over the years

Space salvage would likely be similar to sea salvage. Once they are out of control the are open for capture and control because of the risk they represent to other satellites. Self destruct would be frowned upon as an open act of war due to shrapnel's ability to many other satellites including the space station at random. This would include spy satellites, either keep control, get them out of orbit, repair them or salvage them. Capture techniques are simplified in space because you have plenty of time to a

Here is the deal : we tell the satellite owner the trajectory of the salvage machine beforehand. If they don't move the satellite, it is considered that it is a dangerous one that cannot avoid collision and that it is fair to be salvage instead of being destroyed, like it would have been if this was a regular satellite.

Capturing withough inflicting damage seems rather hard, a major part of it being the approach + synchronization with the satellite.

I was not trivializing the task accomplished. I was saying that when you look at the entire project goals, it's amongst the easier. If they simply return to Earth with the satellite, they'll oblitherate most of the cost benefits associated with recycling -- they still have to pay to launch again, and the payload will be used kit, not new. If they do it in orbit, they'll need to basically build a factory in space and mate it to a recycling center. To date, nobody's even attempted large-scale industrial process in orbit. It is a task that dwarfs the challenges of the ISS. We've also learned that things in orbit tend to accumulate fungus, and not a small amount either. There are modules on the ISS that frankly wouldn't meet health code if people lived on them here. When you consider all the obstacles involved in creating a functional assembly line for this kind of thing, and doing it in an economically viable fashion, yes, capturing is the easy part.

How would it be harder than the normal process of developing and deploying a sat?

Let me put it in terms you can relate to: If I walk into a recycling center, select twenty dead computers at random, disassemble them, and put them on a table, how many working computers can you make? Oh, each of those computers is 5 to 30 years old. They also contain explosives and occasionally radioactive material. Now realize that computers at least have standards for how they're supposed to fit together.

Let me put it in terms you can relate to: If I walk into a recycling center, select twenty dead computers at random, disassemble them, and put them on a table, how many working computers can you make? Oh, each of those computers is 5 to 30 years old. They also contain explosives and occasionally radioactive material. Now realize that computers at least have standards for how they're supposed to fit together.

And someone stuck those computers in hard radiation for most of their life. So various parts don't work or work incompletely.

Well, what you say makes sense, but your computer analogy is flawed. I guess nobody is talking about assembling new Satellites *only* from those recovered parts. Fair enough, that'd be a pretty tough task.

My point is, eventually the manufacture of spacecraft like satellites is to eventually be shifted into space anyway. I think you are exaggerating the hurdles which must be overcome in order to do that. There are even simplifying factors, think clean room, pretty easy to achieve in space. I don't see the

They're right. Compare it to using new parts in a TV design vs recycling existing TV's into new TVs. You might not have access to the schematics of the original device, or the component datasheets. If it's broken, you don't necessarily know offhand what exactly is broken. If it's broken and hasn't been running in a long time, you don't know if there's additional things broken through age. There's possibly less certainty about remaining component lifespan on things that do work.

I would guess that many of those 1300 satellites only need some propellant to be able to stabilize themselves and then they will be good to go again. So the first thing to try would be capture and refueling.

well, it's not wrong or overrated. He's right. To capture a dead bird all you have to do is match orbits. That's easy. Even travelling at 17,000mph, you can maintain a mutual closing speed of an inch a second, which is pretty damn precise. Slow enough that you can manipulate an arm to capture the bird at its launch/retrieval junction rather than just grabbing it at any random point (which would most likely destroy it rather than just cause a little damage).

To retrofit a bird you have to switch out modules/circuit boards, replace solar arrays, refuel ACS tanks, etc., etc., etc.

Generally you wouldn't have to do all of those things, just the ones that have failed. For many birds, that just means they're out of fuel, and that's the easiest thing to retrofit: you don't refill the tanks, you just attach a new one with its own set of thrusters. That's still quite difficult, but definitely technically feasible. Whether it's economically feasible is another story, which is presumably what this project is meant to determine.

I find it hard to believe that there will even be enough of the original design information available to allow for cost-effective retrofitting. We are talking about reusing birdies that may have been orbiting for decades - depending on who made them, there may never have been enough documentation available to reproduce the design. All the knowledge may have been in the heads of a few engineers who aren't around anymore.

Space junk in orbit is on it's way to becoming a very serious issue if we ever get around to having a substantial amount of people in earth orbit across multiple habitats (hotels?). I have long thought we need to build a number of trash collecting orbital craft to collect all this junk down to the tiniest bit then send it all crashing down through the atmosphere to burn up. While this is a more productive solution, the bigger problem of space junk is still all the little tiny things zipping around.

The number of defunct satellites is finite, small, and decreases over time. Satellites are big and have predictable orbits. They're not hard to dodge. If you actually wanted to collect them, you could. Satellites are the least dangerous fraction of the space junk.

The dangerous fraction of the space junk is all of the tiny fragments that have been left behind by, for example, anti-satellite missile tests (lookin' at you, China) among other things (lost bits and pieces, leftovers from stage separations).

That fraction of the space junk can be further divided into the chunks that we can see and track, and the pieces that are too small to track and don't have known paths. It presents the biggest hazard because you can't always see it, certainly can't always dodge it, and it moves at tens of thousands of km/h relative to other satellites--that's a lot of kinetic energy.

So yeah, orbital garbage collector sounds sexy, but it's not going to even put a scratch in the actually dangerous part of the space junk cloud.

...and a sentient being evolved from salvaged space satellites and was given life by a race of living machines...later it returned to Earth to seek "the creator". Unable to determine who its creator could be, the probe declared all carbon-based life an infestation of the creator's universe, leading to assimilation...

yeah... would be a good reference, except that in the Shatner/Kirk timeline, Voyager VI was an interstellar probe, not a piece of space junk. And the fact that it received no immediate reply to its calls for the Creator was not a problem of determination; it was however convinced that the Creator was a silicon based machine life form like itself, not a carbon based infestation such as it had found inhabiting its place of origin. There was also a problem, it saw, in that carbon based life was imperfect, and

They did repair several satellites that their upper stages failed to ignite, and were stranded in low earth orbit (~300 miles). This article is mostly talking about refurbishing satellites in geosynchronous orbit which is about 23,600 miles up. That's WAY above the ability of any current manned spacecraft any nation has at the moment.

I like the idea of this sort of mission being manned. A new lease and reason for expanding the ISS, giving it new life, new purpose. Imagine shuttling back and forth, retrieving satelites, taking them back to the ISS for repair and refurbishment, upgrades and updates, then deployed back into orbit for a new lifetime with extended capabilities, even from a simple firmware upgrade.

However, I suspect that may not be as cost effective. However, I just like the idea of having more of the humann element in orbi

Yep, but the price of satelites went down, and the price of shuttles & astronaughts went up.The shuttle was meant to be reusable too, but in practice every trip needed a component-level teardown & rebuild.

oh, waitasec... what are we talking about here? 22,223 mile radius circle, that's roughly 139631 miles of orbital path. Based on the assumption that each satellite occupies 100 feet of space in the orbital track (that's to include a fairly generous solar array), then that means there's room in that specific orbit for 7,372,528 satellites. I *think* we've got some way to go yet before we fill the geostationary track up with dead birds. At a launch-to-orbit rate of say 1,000 a year (that's more than two launc

Not that hard either to think about slotting over oceans, orbital perturbations, realistic separations, freq separation conflicts, etc. I don't mean to be mean but the problem is not as trivial as your (incorrect) math would indicate. BTW, collision avoidance is very important even for geosynchronous orbits.

The big problem in geostationary orbit is not physical collisions but radio interference. If you put too many satellites in it they won't be able to communicate with Earth. Also, geostationary orbit is not perfectly stable, you have to correct against the effects of the Moon and the Sun.

um... this is why they have DCS and CTCSS squelch, like you have on personal mobile radios. You can transmit on the same carrier, any number of channels you like; the way you separate them is to transmit a tonal subcarrier (an audio tone which modulates the carrier or in the case of DCS a stream of FSK digital data) which the receiver detects if tuned to that subcarrier, and reject any other signal. Using this method the quality of the received signal depends entirely on the quality of the receiving hardwar

Yes, space is big. But 1300 is just the start, and from my understanding there are 'preferred' paths out into orbit, so i'm sure that a lot of this junk isn't exactly trivial. And unlike hitting one of those beetles and walking away from the accident, you don't get a 2nd chance up there.

DARPA reports that more than $300 billion worth of satellites are in the geosynchronous orbit, many retired due to failure of one component even if 90% of the satellite works just as well as the day it was launched. DARPA's Phoenix program seeks to develop technologies to cooperatively harvest and re-use valuable components [darpa.mil] such as antennas or solar arrays from retired, nonworking satellites in GEO and demonstrate the ability to create new space systems at greatly reduced cost [darpa.mil]. "If this program is successful, space debris becomes space resource," says DARPA Director, Regina E. Dugan. However satellites in GEO are not designed to be disassembled or repaired, so it's not a matter of simply removing some nuts and bolts says David Barnhart. "This requires new remote imaging and robotics technology and special tools to grip, cut, and modify complex systems." For a person operating such robotics, the complexity is similar to trying to assemble via remote control multiple Legos at the same time while looking through a telescope. "If you've got a satellite up there already, don't worry, this isn't going to be some illicit grave-robbing mission to create hordes of evil Frankensatellites [dvice.com]," reports Dvice. "DARPA says the agency will make sure and get permission before it chops anything up for scrap."

DARPA and NASA also sponsor an annual Zero Robotics high school tournament that starts on September 8. Just like in this challenge the final competition will take place live on the space station. More details are on the Zero Robotics website: www.zerorobotics.org [zerorobotics.org]